A gas turbine engine is a prime mover including as a basic configuration a compressor which sucks and compresses air to increase the pressure of the air, a combustor which burns fuel with the compressed air to produce high-temperature and high-pressure gas, and a turbine which intensely hits the high-temperature and high-pressure gas against an impeller to rotate the impeller. The prime mover takes power from the turbine.
An axial compressor of the gas turbine engine is a type of a compressor in which air flows in parallel to an axis of rotation and which generally includes a plurality of rows of rotor blades provided on the outer circumferential surface of a rotating body, and a plurality of rows of stator blades provided on the inner circumferential surface of a casing. In such a compressor, by action of the stator blades and the rotor blades which rotate relative to the stator blades, air can be sucked and the sucked air can be compressed to increase the pressure.
The compressor having the above configuration may be configured to appropriately set the angles of attack of the rotor blades by changing the mounting angles of a guide blade at an inlet and the mounting angles of the stator blades on first several rows, in accordance with the flow of air. In addition, it is proposed that the mounting angles of stator blades and the angles of attack of rotor blades are appropriately changed also in the turbine in a manner similar to that in the compressor. For example, PTL 1 discloses a turbine including this type of variable stator blade operating device.
The variable stator blade operating device disclosed in PTL 1 includes a casing that causes the front end portion of a shaft of each variable stator blade to penetrate the casing such that the casing supports the front end portion, an operation lever that is mounted to the front end portion of the shaft of each variable stator blade, a rotating ring that has a diameter slightly greater than that of the casing, a pin that causes each operation lever to be pivotally supported on the rotating ring, and an actuator that rotates the rotating ring. The variable stator blade operating device further includes a plurality of elastic bodies arranged at equal intervals in the circumferential direction between the rotating ring and the casing. A front end of an alignment bolt penetrating the rotating ring in the radial direction is engaged with the outer surface of each elastic body, and the inside of each elastic body is pressed against the casing.